This invention relates to an optical fiber demountable connector.
In an optical fiber connector there needs, on account of the very small diameter of optical fibers, to be very critical alignment of the end of one fiber with that of another in order to achieve a satisfactory coupling efficiency. This alignment is achieved by the provision of reference surface on the fiber terminations relative to which the positions of the fibers are accurately known. In the connector these reference surfaces are brought into alignment by registering them with a third reference surface. In principle the reference surfaces on the fiber terminations could be provided by the side walls of the bare fibers themselves, but in practice this would be difficult in a demountable connector on account of the extreme fragility of bare fibers. Instead it is usually preferred to provide each optical fiber end with a larger, more robust, reference surface in the form of a circularly symmetrical collar into one end of which an optical fiber extends and is secured so that, at the other end of the collar, the fiber and the collar axis are accurately aligned. In this context it is to be noted that a plastic coated optical fiber is not necessarily concentric within its plastic coating, and hence care must be taken to ensure that in the securing the end of a plastic coated fiber within a collar the alignment of the collar is determined with reference to the fiber itself rather than with reference to its coating. The purpose of the present invention is to provide a demountable connector for accurately aligning and holding the termination collars of a pair of optical fibers in butting relationship.